Heterodermia verdonii Elix, Australas. Lichenol.

Mongkolsuk, Pachara, Meesim, Sanya, Poengsungnoen, Vasun, Buaruang, Kawinnat, Schumm, Felix & Kalb, Klaus, 2015, The lichen family Physciaceae in Thailand-II. Contributions to the genus Heterodermia sensu lato, Phytotaxa 235 (1), pp. 448-450 : 448-450

14. Heterodermia verdonii Elix, Australas. Lichenol. 68: 18 (2011) ( Fig. 9D )

Type:— AUSTRALIA. New South Wales: 25 km NW of Coffs Harbour, below Waihou trig. stn., 30°06’S, 153°02’E, 340 m, on sandstone outcrop in closed Tristania-Ficus forest , 12 Oct. 1978, D. Verdon 3814 ( CANB!);— Chaudhuria indica Zahlbr., Ann. Mycol. 30 (5–6): 434 (1932). Type:— INDIA. Darjeeling: supra muscos, 2286 m, G. L . Chopra (holotype W!) .

Thallus foliose, orbicular to irregularly spreading, loosely adnate, to 5 cm wide, but often forming colonies to 10 cm wide. Lobes 0.5–1.2 mm wide, plane to weakly convex or weakly concave, sublinear-elongate, sympodially branched, radiating; apices plane, usually discrete, eciliate; phyllidia, isidia and soredia absent, but with distinct pseudocyphellae along the margins of the lobes. Upper surface greenish white, whitish to gray. Medulla white. Lower surface corticate, whitish to pale brown, dirty brown near the centre, smooth. Rhizines mainly marginal, concolorous with the thallus or darkening near the apices, irregularly branched, 1–2 mm long. Apothecia laminal, substipitate, 0.5–2.5 mm wide; margin ± crenate with pseudocyphellae; disc concave, brown to blackish brown, ± thinly gray-pruinose. Ascospores Pachysporaria - type, ellipsoidal, 20–30 × 13–15 µm. Pycnidia common, initially immersed, becoming emergent, visible as black dots; pynoconidia bacilliform, 4–5 × 1 µm.

Chemistry: Cortex and medulla K + yellow, C –, KC–, P + yellow; containing atranorin (major), zeorin (major), dissectic acid (submajor), 16β-acetoxyhopane-6α,22-diol (major), leucotylin (minor), 6α-acetoxyhopane-16β,22- diol (major), 6α,16β-diacetoxyhopane-22-ol (minor).

Nomenclature notes:— Zahlbruckner (1932) described a new monotypic genus for this species, because he was puzzled by the bluish-green discoloration of the thallus of the specimen available to him and thus presuming it contained a cyanobacterium as the photobiont. But the study of the type specimen revealed green algae as photobiont and a typical Heterodermia chemistry, i.e. atranorin (major), zeorin (major), dissectic acid (major), 16βacetoxyhopane-6α,22-diol (major), leucotylin (minor), japonene (trace) and 6α,16β-diacetoxyhopane-22-ol (trace). Kurokawa (1962) who did not see the type, placed Chauduria indica into synonymy with Heterodermia diademata . Indeed that species is superficially very similar to Heterodermia verdonii , but is easily separated by a different terpene array and especially by the lack of dissectic acid. Heterodermia angustiloba is also similar morphologically, but contains additional norstictic acid.

However, Chaudhuria indica , the older name cannot be combined into Heterodermia because another species has been described as Heterodermia indica (H. Magn.) D.D. Awasthi.

Distribution and habitat:—This rare lichen occurs on bark ( Betula alnoides is reported) and rock in hill evergreen forest, lower montane forest and dry evergreen forest from 800–1610 m above sea level; also in India and Australia.

Remarks: — characterized by the narrow, eciliate lobes, the lack of phyllidia, isidia and soredia, and the occurrence of dissectic acid and triterpenes.

32 • Phytotaxa 235 (1) © 2015 Magnolia Press

MONGKOLSUK ET AL.

Material from Thailand examined:— Nan: Doi Phu Kha, area of view point at Doi Phu Kha , in hill evergreen forest, on bark of Betula alnoides , 1470 m, 19°18'13'' N, 101°09'55'' E, 10 May 2006, S . Meesim RU-DK 15, ( RAMK 21382 ); ibid., S . Meesim RU-DK 7, ( RAMK 21477 ); Chiang Mai: Doi Inthanon National Park, along trail to Siriphum waterfall, in hill evergreen forest, on bark of unidentified tree, 1320 m, 18°32'50'' N, 98°30'56'' E, 9 September 2005, N . Juntawong RU-NJ 464, ( RAMK 21689 ); ibid., Doi Suthep-Pui, along trail from research centre of Suan Song Saeng Kasetsart University to National guard units 1 Pha Dum , in hill evergreen forest, on bark of unidentified tree, 1415 m, 18°45'04'' N, 98°53'16'' E, 30 April 2005, W . Hongsachart RU-WD 57, ( RAMK 21710 ); Phitsanulok: Phu Hin Rongkla, forest protection unit Man Daeng , in lower montane forest, on rock, 1610 m, 16°55'51'' N, 101°03'04'' E, 16 July 2004, P. Mongkolsuk RU-PM 256/4, ( RAMK 21812 ); Nakon Ratchasima : Khao Yai National Park , around Ban Chom View , in dry evergreen forest, on bark of unidentified tree, 800 m, 14°25'19'' N, 101°23'51'' E, 11 January 2003, S . Udompaisan RU-21567, ( RAMK 7172 ) .

II. The lichen genus Leucodermia

Figures

FIGURE 9. A. Heterodermia speciosa (scale 5 mm). B. Heterodermia tremulans (scale 5 mm). C. Heterodermia tropica (scale 5 mm). D. Heterodermia verdonii (scale 5 mm). E. Leucodermia borphyllidiata (scale 5 mm). F. Leucodermia borphyllidiata, lateral phyllidia, seen from below (scale 1 mm).